N-Hance: Software for Identification of Critical BSR Locations in Automotive Assemblies using Finite Element Models 2003-01-1522

Today's highly competitive automotive industry is constantly looking for ways to improve the perceived quality of its vehicles. Perceived quality defined as the sense of touch, feel and sound that the customer perceives in a vehicle is seen as one of the areas with maximum potential for increasing customer satisfaction. Buzz, Squeak and Rattle (BSR) is one of the major contributors towards the perceived quality in a vehicle. Almost all of the annoying noises that the customer hears can be classified into a buzz, squeak or rattle. Traditionally BSR in subsystems and components of a vehicle have been identified and rectified through extensive hardware testing. With the auto companies and suppliers being challenged to cut structural costs, eliminate costly hardware builds, and bring products to market faster by reducing development cycles, increasing math analysis of subsystems and components for such perceived quality issues is desirable.

In line with the needs of the industry to perform math-based analysis and to improve the perceived quality of vehicles, Lohitsa and GM partnered to validate N-hance. BSR. N-hance.BSR is a software tool developed exclusively to identify BSR critical-locations, for the finite element model that is subjected to a vibration profile of interest. The software has been fully automated to rank order the issues based on their severity and thus enables analysis and interpretation of the results, with minimum user input. N-hance.BSR is a fully contained software including pre and post processors, user friendly GUI and report generating capabilities. The tool was used to predict critical-locations on two different subsystems and the results from the analysis were then correlated to BSR issues identified through hardware testing. In both cases the correlation was greater than 75%, taking into account only those issues from hardware components that were adequately represented in the finite element model. An overview of the method is presented followed by results from the BSR evaluation of an instrument panel and a door.